Thin small-outline package (“TSOP”) components are used hi the assembly of many electronic consumer products having standard circuits, such as digital televisions, portables and computers. TSOP components also form the foundation of complex computing circuits such as motherboards and modules. For such standard applications, TSOP component are typically supplied in bulk as commercial off-the-shelf (“COTS”) components.
COTS TSOP components are usually produced in a relatively large-size silicon die using lead frame materials such as Alloy 42 (which may be approximately 41% nickel 0.2% silicon and 0.4% manganese, and the remainder iron), Be:Cu (beryllium/copper). Alloy 25 or equivalent alloys, and Cu (copper). Alloy 42 is most often used due to the thermal coefficient of expansion (“TCE”) of 6-7 ppm/deg C. Also, COTS TSOP components usually employ a gull-wing electrical lead with a relatively short length and a thickness of about 0.006±0.002 inch. The construction of COTS with these specification and loose quality control allows manufacturers to keep the cost of manufacturing low. Unfortunately, the short electrical lead length, TCE, and variability of the electrical lead thickness affect the reliability of the electrical leads and the solder joints that connect them.
As such, COTS components are not usually configured for the rugged conditions and the required reliability demanded by military applications and electronic systems used in harsh environments. Electronics located in these applications require a higher degree of reliability. Because of the variability of COTS components, some of the COTS components will satisfy the higher degree of reliability and some will not. Those COTS components that meet the higher degree of reliability are called rugged off-the-shelf (“ROTS”) components.
One reason the majority of COTS components are not ROTS components is the moment of inertia or stiffness of the electrical leads on the COTS components. The short length and high stiffness of the electrical leads on COTS components may create undue tension and stress on solder joints and connections. Further, the stiffness of the electrical leads transmits forces and vibrations easily, creating stresses and fatigue in the component leads and overall structure. These stresses may cause failure of joints and the electrical leads and thus shorten the life and reduce reliability of the COTS components.
ROTS quality components, however, typically have more flexible electrical leads and therefore enjoy a longer life and greater reliability. Unfortunately, ROTS components require expensive testing and effort to identify the ROTS quality components from a group of COTS components. Further, due to the need for testing and evaluation, ROTS quality components require significant time to verify and, consequently, sufficient quantities may not be readily available for all applications at any given time.
Therefore, there exists a need for a method of and apparatus for modifying COTS components info components with ROTS quality electrical leads.